'It's Charlie. How you getting on?'

'I, er,' the voice hesitated. 'I lost him about 15 minutes ago. Don't worry, I'll find him again. He gave me the slip near Middle Abbey Street. I think there might ...'

'For fuck's sake,' Deegan interrupted. 'I only asked you to do one feckin' thing.'

'Yeah, as a favour, Charlie,' the voice said unhappily. 'As a favour.'

'Just find him, okay.'

'What do you think I'm trying to do?'

'If this fucker kills again ...' Deegan let the sentence hang.

'If you think this idiot's the killer, why have you only got me tailing him? Does Colm McEvoy know what you're up to? You'd better know what the fuck you're doing Charlie, because if I get into hot water, I'm dragging you in with me,' the voice threatened.

'Just find him, okay.' Deegan terminated the call. 'For fuck's sake,' he hissed to himself. Dermot Brady was running round loose. If anything happened and that note or the emails came to light he'd be in big bloody trouble. On the other hand, if he collared Brady, and he was the killer, no one would care how he solved it, just that he had. The next promotion would be in the bag and he wouldn't have to take any more crap from McEvoy. It was worth the risk.

He was confident nobody had followed him to the edge of the park. He turned off the engine and switched off the lights. The side street was quiet, the street lights dim, the houses hidden behind high hedges.

It was time again. He unclipped his seatbelt and pulled on a black polo neck sweater, tugging it down over his ears. He reached across the passenger seat and dragged a black coat towards him, slipping into it. The park would be cold at this late hour.

Since the discovery of David Hennessey's body and the second chapter the story had been the centre of the media's attention. He was confident, however, that as long as he kept moving, they would not be able to keep up. The third slaying would add further confusion and division and without a definite line of enquiry, he could operate with impunity.

He'd expected to be interviewed by a guard perversely welcomed it and it had been as easy as he'd expected. He'd scripted everything in advance and he'd just stuck to the script. The guard had hurried through his questions with only half his attention seemingly on the process and he'd then left him alone.

He'd taken a risk following McEvoy earlier that morning, but he would stay away from them from now on as much as possible. After all, there was no point having rules if one was going to constantly keep breaking them; he needed to play his own game, not constantly worry about theirs.

He pushed open the car door and eased himself out. From the back seat he collected a small, black rucksack and a red baseball cap. His body tingled with anticipatory tension, his controlled rage starting to pin-prick in crimson bursts. He took a deep breath, letting it out slowly, collecting himself, pushing the anger deep down into the pit of his stomach, well away from his focused mind. He needed to manage his fury, harness it, and not lose himself in it. That would lead to mistakes.

He closed the car door and set off towards the darkness beyond the gates.

The light was fading fast and the Phoenix Park was becoming quieter. An irregular stream of cars coasted along the main thoroughfare; a couple turned off to find a secluded spot out of the view of prying eyes. A few late walkers bundled along in pairs trying to burn off calories; some took a more leisurely pace, throwing balls for dogs. A handful of cyclists kitted out in the lurid colours of some team sped around doing laps. A handful of runners in one or twos pounded wearily around their circuits, their legs trying to match the rhythm being pumped into their heads via earphones. The sound of the surrounding city could hardly be heard beyond the park's walls.

Lurking in the dark shadows of the trees, away from the path, a figure pulled his baseball cap lower across his eyes, checked both left and right and stepped out quickly across a dirt path that ran parallel to a paved one just a couple of yards away, a road immediately beyond that.

He placed the looped end of a black-coated, steel wire around a tree trunk at chest height, fed the rest of the bunched wire through the loop, and retraced his steps back across the path to the nearest tree, feeding out the wire. He passed the free end of the wire around the trunk and pulled it tight. Keeping the tension, he spun the steel cable round twice more and tied it off. Visible for barely a couple of seconds, he backed away into the shadows and lay flat on the ground, blending into the dark, a pair of wire cutters clutched in his hand.

Twenty seconds later a runner came into view. The man was pounding out a steady rhythm, his feet slapping against the tarmac of the path. He ran past where the wire was primed, oblivious to its presence, and disappeared into the dusk.

After a short while a second runner appeared. Rolling from side to side, gasping for air, her eyes focused on the dirt path three yards distant. Robbie Williams, singing Rock DJ, urged her on via earphones snaking from the pink iPod mini strapped to her upper arm. She wore a light grey t-shirt with the letters UCSB written across the front in blue, the underarms and neck dark grey with sweat, a pair of black, tight-fitting Lycra shorts that stopped just short of her knees, and a pair of white running shoes.

She had last been in reasonably good shape ten years ago when she had played hockey while studying in the United States. She was now three stone heavier and a long way short of fit. She was hoping that the stitch in her side would ease shortly. That or she was going to have to stop for a breather. She shouldn't have pushed so hard earlier on, she should have taken a more measured approach. She'd only been running round the park for two-and-half weeks, setting out every other night. The first time she had only managed one circuit, sucking in air while her heart threatened to break through her ribs.

The wire caught her high on her chest just under her collarbones. The air shot out of her lungs, her face twisting into a look of surprise and pain, legs running through empty space. She fell almost horizontally, slamming into the ground heavily, her head thumping off the packed earth.

Her assailant darted out onto the dirt path, glancing left and right. He slammed the wire cutters into the stunned woman's face, breaking her nose and shattering a cheekbone. Satisfied she was pacified he threw the cutters toward the base of the nearest tree and grabbed the woman by the shoulders, dragging her quickly off the path, away from the road into the darkness of the trees. His gloved hands closed round her throat and squeezed tightly. Off to his left a car swept round the roundabout and carried on down the avenue.

The woman, dazed and confused, managed to raise one arm and half-heartedly clawed at her attacker's hands, trying to relieve the pressure on her neck, her head feeling as if it were going to explode. With her other hand she tried to hit out at him. She tasted blood in her mouth and a few seconds later she gave up altogether, her arms falling limp.

The figure maintained the pressure, watching the woman's eyes bulge, white foam forming at the corners of her mouth, a trickle of blood escaping from her already bloodied nose. A minute later he checked for her pulse but found none. He quickly retrieved his wire cutters and wire and a small rucksack. Taking a heavy, dark sheet from the bag, he laid it over the body. He could hear another runner approaching through the gloom. He dropped to the ground, heart thumping, grasping the wire cutters. The feet slapped by and receded into the night.

McEvoy sat in his car, his head tipped back, plastic cigarette clenched between his lips. It was taking all his willpower not to replace the stick with a real smoke. He was exhausted. Totally shattered physically, mentally, emotionally. He wasn't programmed any more for back-to-back 15-hour days or for trying to run parallel investigations on horrific murders. He doubted he ever was. The stress was eating him up, gnawing at his innards. He glanced in the car's rear mirror at himself. Forty-one years old, pushing 60. He was a shadow of what he used to be. His face was hollow and grey, his eyes sunken. He needed to start taking care of himself. He just couldn't work up the motivation or energy any more.

He should have headed off a couple of hours ago. Gone home, tried to relax, drunk a couple of whiskies and let things tumble around inside his head; allow the connections to float to the surface. Instead he'd tried to force them to rise, spending the last two hours looking through witness statements, trying to spot anything that might give them a breakthrough, determined to be the last to leave the incident room. Simon Grainger, Jane Murphy and Barney Plunkett had pulled out of the car park five minutes earlier. Calls were being diverted to a central call centre, the incident room guarded by a couple of locals.

He'd gotten so wrapped up in things he'd forgotten to ring Gemma, let her know his plans. No point now, he might as well just drive straight there. He sighed and tipped his head forward, started the car, and reversed back from the space. He'd visit Caroline's and see Gemma. Then ring his mother, and then maybe onto Maggie's grave, before returning home where he hoped his exhaustion would override his usual insomnia.

He stared off to his right through the gloom along the lime tree avenue. He could barely make out the crucifix with its little roof. It was nearly 48 hours since Laura Schmidt had been killed and they didn't have a single solid lead. There had to be something lurking in the jumble of samples and witness statements, some wisp of evidence that would show them the way. The problem was that it might take them days or weeks to unearth it and by then the killer would have struck again.

He needed some sleep. Maybe it would help clear the fog in his mind. And a nip of whisky. And a few cigarettes. He switched on the headlights and drove out slowly through the gate and past the orchard. As he reached the main gate his mobile rang.

He slowed to a stop and answered it. 'McEvoy.'

'Sir, you asked for any missing persons cases to be reported to you.'

'Yes.' He tipped his head back again and closed his eyes. He knew what was coming.

'A man has just reported his wife missing. She was jogging in the Phoenix Park. He's tried calling her on her mobile phone and he's been out looking for her but he can't find her. She always did the same circuit.'

'How long has she been missing?'

'An hour; hour and a half. She was due back at their house between 8.30 and 9 p.m. She's never been late before.'

'And she hasn't run off anywhere or met a friend? She's only been missing a short while.'

'We've told him it's too early to start a search, and I wouldn't be bothering you, but, you know, you requested ...' she trailed off, before continuing. 'He says she would've never have switched off her mobile phone. She was only wearing a t-shirt and shorts. She would have rung if she was doing something else.' The dispatcher paused. 'He's very worried, Sir.'

'And she was running in the Phoenix Park?'

'Yes.'

'Okay, what's her name and age?' McEvoy asked, giving in, knowing that he had to check it out for his own peace of mind.

'Grainne Malone. She was 32. Married with no children. She lives on Benburb Street in an apartment block. It's next to Collins Barracks.'

'Right, you'd better send out a couple of patrol cars,' McEvoy instructed. 'Tell them to go down every road and pathway and see if they can see anything. Give them a description. There's CCTV cameras at every gate, get a photo and get someone to check and see if you can spot her leaving. Find out what gate she would have been using. I'll be there in about 20 minutes; I'm still out in Maynooth. I'll meet them near the zoo entrance. Tell the husband not to panic and to tell us the minute she turns up.'

'He's worried she's been abducted.'

'She's probably met a friend and gone for a drink,' McEvoy said, a deepening pit opening in his stomach. 'Tell him we're sending someone round for a photo and that we've sent a couple of squad cars out to have a look for her. Reassure him that we deal with cases like this all the time and people usually turn up in a couple of hours with a tall story. We'll get back to him shortly.'

'Okay, I'll get onto it right away.'

McEvoy disconnected the call and accelerated towards the gate switching on the blue lights. Usually they would put the husband on the long finger for at least 24 hours, but he had a bad feeling about this. At over 1700 acres the Phoenix Park was one of the largest enclosed city parks in Europe, a large wedge of land stretching from the city centre to the old outer suburbs. It was about as isolated a spot in the city as you could find, with open rolling pasture, forests and gardens. It seemed to fit the modus operandi of the killer a public space yet isolated and open. Except for the fact that it also contained Deerfield House, the American Ambassador's residence, aras an Uachtarain, the residence of the President of Ireland, Farmleigh House where guests of the state stayed when they were visiting the country, and Garda Headquarters, along with the offices of Ordnance Survey Ireland and Dublin Zoo.

But these were only pockets of high security; little islands in the park's vast size. The killer probably relished the challenge of murdering within their shadow, though given the size and terrain the risks were no more than Glencree or Maynooth, and it would be easy to stick to the shadows of the trees and vault a wall rather than use one of the gates. As long as the killer stayed away from the high security sites he could wander round the park to his heart's content and no one would be any the wiser.

They were walking slowly along the dark, tree-lined roadway tracing the missing runner's route. A male guard was on the far side of the road, McEvoy and a female guard together. They crept along the tarmac path, their torch beams penetrating deep into the darkness, the trees rising above them. All they'd spotted so far was litter.

McEvoy sucked on the plastic cigarette, plucked it from his lips, and held it as if sheltering the tip from a wind. He checked his watch again. Ten to midnight. His tiredness had caught back up with him, along with a morose funk. He swivelled his neck and rolled his shoulders trying to ease the stiffness.

'Trying to give up, Sir?' the woman asked, seeking to start a conversation and fill the cloying silence.

'Trying,' McEvoy mumbled. 'Half succeeding.'

'I used the patches.'

'Did they work?' he asked, a fraction interested.

'Except for when I drink,' she replied. 'And when I'm stressed out or nervous.'

'Are you asking me whether I have any cigarettes?' he replied, cupping the packet in his pocket and pulling them free.

'I've not been drinking, Sir,' she said, teasing a cigarette from the box.

McEvoy dropped the plastic cigarette inside the box and plucked one out for himself. He sparked a lighter and held it out to the woman. She lit her cigarette, her face glowing orange shadows, and he did the same. He drew the smoke deep into his lungs and they moved on in silence, their torch beams dancing in the gloom beneath the canopy.

Five yards further along the path the woman's beam stopped and moved back a few degrees. 'Sir!'

McEvoy swung his beam to find hers. Up ahead, off to the right was a low, dark mound. If the whole area around it hadn't been flat, they probably wouldn't have paid it a second glance. As it was, it was patently out of place.

'Do you think it's her?' she asked.

'We'll soon find out,' McEvoy replied, already knowing the answer, his stomach knotting with the knowledge.

They headed along the path until they were perpendicular to the mound. He swept his torch beam across the ground between themselves and the suspected body. It was clear where she had been pulled from the dirt path and through the grass, the blades flattened and previous year's autumn leaves dragged aside.

'I'm going to go back up a bit and cut across,' McEvoy said to the woman, indicating with his arm where he meant. 'Keep your torch fixed on the mound so I know where I'm going.'

'Okay,' she mumbled, an involuntary shiver running up her spine.

'And get rid of this for me.' McEvoy handed her his smouldering cigarette. 'Don't leave it on the ground.' He took a pair of sealed, rubber gloves from his suit pocket, opened the packet and slipped them on. A few yards along the path he headed in under the trees. The grass, wet from dew, soaked his shoes and the bottom of his suit trousers. He eased his way forward, scanning carefully his route before veering left toward the mound.

As he neared, he slowed to crawl, worried about disturbing any evidence. He lowered himself onto his haunches and, holding the torch in his right hand, lifted the heavy plastic sheet with his left. A bloodied foot and ankle came into view. The toes had all been severed crudely.

He let the sheet drop, moved to the other end and lifted the sheet again. The woman's eyes were bloodshot and bulging in their sockets, the middle of her face a bloody mess, the residue of froth stained the edges of her mouth. Her hair was half-pulled from her ponytail. He pushed his left elbow in under the sheet to tent it above the body, the torch beam illuminating the temporary chamber he'd created. He could see that she was still wearing her t-shirt and shorts; an iPod was strapped to her arm, though the headphones seemed to be missing. With his right hand he checked for a pulse. He couldn't find one.

He let the sheet fall back into place and closed his eyes, massaging them through the lids. Three days, three dead. There'd be another tomorrow; today, in a minute, given the time. He hoped to God that the killer had left them more to go on with this victim than the previous two. It was all they could do to process the crime scenes and potential witnesses in a day, let alone stop another murder taking place.

He swivelled slowly on the balls of his feet and shone the torch beam further into the darkness. A few feet away a tree trunk reflected back a small, white oblong. Hung beneath it was a small, clear plastic bag that looked to contain one of the missing toes and a folded note.

'Are you okay, Sir?' the female guard asked, concern in her voice, unnerved by McEvoy's silence. 'Is it our missing runner?'

'You'd better ring it through,' McEvoy replied flatly, levering himself back upright. 'We're going to need a crime scene team out here. Arc lights, the lot. Also get the gates shut and round up anyone still in the park. I want this whole place locked down. And get somebody to call through to aras an Uachtarain and the ambassador's residence and let them know what's happened.'

Feeling nauseous and impotent, he started to retrace his steps back to the path.

Chapter Three.

Wednesday, April 16th McEvoy stepped back onto the tarmac path. Both of his companions were on their mobile phones carrying out his instructions. He pulled his own phone from a pocket. The call was answered after several rings.

'Bishop.'

'It's Colm McEvoy. We have another body,' he said steadily. 'A woman in her early thirties killed whilst running in the Phoenix Park. He strangled her to death.'

'Jesus Christ,' Bishop muttered, still struggling to escape from his sleep.

'He cut off all her toes and left his calling card. We found her hidden under a sheet.'

'I think Jenny Flanagan's the next available DI,' Bishop said, trying to think through the situation. 'I'll give her ...'

'It's okay,' McEvoy interrupted, taking control. 'I'll give her a call now. I just wanted to let you know that he's killed again. And that he's going to kill one person each day until he's finished his task,' he finished balefully.

'I, er,' Bishop mumbled, unsure what to say. After a pause he continued. 'Look, you know what to do. We have a press conference in the morning. I'll need to be fully briefed on this murder and the one yesterday.'

'I'll be there an hour beforehand,' McEvoy replied.

'Good. I'll see you then. Good luck, Colm,' Bishop said and ended the call.

McEvoy stared off through the trees and wondered whether Bishop would be able to go back to sleep now or whether the new death would eat into him like a cancer, gnawing at his brain through the long hours of the early morning.

A garda patrol car turned at the roundabout and shot towards them, its siren howling, its blue lights sweeping the trees. It pulled to a stop, its siren dying, the blue lights continuing to flash, a beacon for the other approaching vehicles.

He placed the call to Jenny Flanagan. It was answered almost straight away.

'Hello?'

'Jenny, it's Colm McEvoy. I'm afraid I'm the bringer of bad news.'

'He's killed again,' she predicted, an anxious delight in her voice.

'The body's in the Phoenix Park near to the papal cross,' McEvoy confirmed. 'You can't miss the blue lights. Round up the rest of your team and I'll see you shortly.'

'We'll be there as fast as we can,' Flanagan replied eagerly.

Another garda car pulled to a halt followed by an ambulance.

He had a clear view through the nightscope across the expanse of the park. In various shades of green he watched a figure walk to the edge of the car park and come to a halt, staring out into the darkness. Behind him the flashing lights of a garda car spun, pulsing out its call sign.

His heart was thumping in his chest, his breathing laboured from his trip around the park. He was amazed that they had found the body so fast. It was probably still warm to the touch. He'd been expecting it to lie there until first light when an early runner would have pounded along the path to discover his night's work. He could live with their good fortune; they'd have a small head start on that part of the investigation, but he was still safe in his anonymity.

There had been something more satisfying about this killing. The woman had tried to fight back and it had been more visceral, more real. He could actually feel the life being wrung out of her; see the panic and confusion in her eyes. She had wanted to hang onto life, unlike Laura. But while it might have been more gratifying, he knew that he could not take that risk again. The remaining victims needed to be rendered incapacitated immediately, unable to defend themselves.